Correct a bill that has already been entered and paid

We are a 501(c)3 animals rescue, working alongside animal control within our city. The ACO handles the dogs, we handle the cats.

We have received a grant allowing free spay/neuter, flea treatment, vaccines and microchip for cats within our city. Last week, we received our invoice (bill) from the clinic. We paid the bill by check as it was shown on the invoices, and entered it under our QB bills. Since it was paid by check, now the bill shows as paid. After paying the bill, we were informed that one of the entries on the invoice was incorrect. It was entered as flea treatment, instead of microchip, which is $5.00 more. Therefore we will simply owe an additional $5.00 on the following invoice. Today, I received the corrected invoice as it should have been, with the additional $5.00 included, along with our new invoice (bill).

If I make the change on the original invoice, then the total payment does not add up to the full invoice, and it is therefore not, in fact, paid.

My new invoice includes all the current charges, as well as the $5.00 I still owe. How do I handle the correction, as well as the new charges. Mind you, I need to include the correction, (remove the flea treatment and include the microchip) so I can Item track, when making out my reports for the grant.